A notorious Windows leaker claimed on Sunday that Microsoft will issue yet another update to Windows 8.1 later this year, evidence of an even-faster acceleration in the company's development tempo.

The leaker, dubbed "Wzor," said Microsoft will ship a second update to Windows 8.1 this fall that will include a new Start menu, one blending elements of the classic navigational tool and tiles from the new "Modern," ne "Metro," user interface (UI).

The WinBeta and myce websites first reported on Wzor's claims yesterday.

Microsoft showed a brief sneak peak of what it said was a future refresh of Windows 8.1 update at its Build developers conference earlier this month. Among the changes, said Terry Myerson, the head of Microsoft's operating systems engineering group, would be a restored Start menu and windowed Metro apps on the desktop.

Both had been rumored to be coming to a future version of Windows; those claims first surfaced in December 2013.

According to a message posted by Wzor April 20 on a Russian discussion board, Microsoft is arguing internally whether to call the next iteration "Windows 8.1 Update 2" or "Windows 8.2."

If accurate, it would be the first time that Microsoft has issued two major updates for Windows in the same calendar year, another strong signal that it's deadly serious about increasing the speed of its development and release schedules and putting Windows in a mode akin to mobile operating systems, which historically have been much more frequent than those for traditional personal computers. The move would be in keeping with CEO Satya Nadella's "mobile first, cloud first" mantra.

Enterprise IT personnel objected to a short 30-day requirement Microsoft laid down for upgrading to Windows 8.1 Update in order to receive future security patches; days later, Microsoft extended the deadline to 120 days.

Although Wzor was the source of the latest claims, the Wzor.net website remains offline. It went dark in late March, just a day after U.S. authorities arrested Russian national Alex Kibkalo and accused him of spilling Microsoft trade secrets.

Wzor alluded to the arrest of Kibkalo in the April 20 message, claiming that changes in how Microsoft shared information with partners -- the likely source of the previous leaks -- prevented the disclosure of more information, including screenshots.